j.p.buzen (honeywell) and u.o.gagliardi (harvard), the evolution of virtual machine architecture, 1973

Essentially, third generation architectures created two distinct modes of system operation (privileged/non-privi- leged, master/slave, system/user, etc.)

the discussion about virtualization started in the early 1960s somewhere in england ... at least in the case of computing.

hypervisor (aka vmm): because It is conceptually one level higher than a supervisor | en.wikipedia

the wording supervisor seems to rely on a convention comp. architects agreed on:

the processor is a conventional one with two modes of operation, supervisor and user. in supervisor mode the complete instruction repertoire is available to the precessor. In user mode, it is not | gerald j. popek, robert p. goldberg, formal requirements for virtualizable third generation architecture, casm, Vol17/7, 1974